This page brings together the key official documents, consultation archives, and practical tools you need to understand and work with the Home Energy Model and the Future Homes Standard. We update these links as new material is published.
Official Documents Library
The core government and standards documents that define how HEM works and how the Future Homes Standard will be implemented.
Building Regulations & Approved Documents
- Approved Document L: Conservation of Fuel and Power — The current Part L requirements for new dwellings, setting minimum fabric and services standards. See our Part L changes guide for what changes under FHS.
- Approved Document F: Ventilation — Ventilation requirements for dwellings, including background ventilation rates and mechanical systems. Our ventilation guide covers the FHS changes.
- Approved Document O: Overheating — Introduced in 2022, setting maximum internal temperatures for new homes. See our overheating guide.
- Approved Document S: Infrastructure for Charging Electric Vehicles — EV charging provisions that interact with overall energy demand calculations.
HEM Technical Documentation
- Home Energy Model: Technical Documentation — The full technical specification for HEM, covering the calculation methodology, input parameters, and output metrics.
- HEM Open-Source Repository (GitHub) — The open-source Python implementation of the Home Energy Model calculation engine, published by DLUHC.
- Standard Assessment Procedure (SAP 10.2) — The current SAP methodology, still in use until HEM fully replaces it. See our SAP vs HEM comparison.
Consultation Archive
Key government consultations that have shaped the Future Homes Standard and the Home Energy Model. Understanding the consultation history helps explain why certain decisions were made.
Future Homes Standard Consultations
- The Future Homes and Buildings Standards: 2023 Consultation — The major consultation setting out the proposed technical standards, including the shift from SAP to HEM. The government response confirmed the standards in late 2024.
- The Future Homes Standard: 2019 Consultation — The original consultation that proposed banning fossil fuel heating in new homes from 2025, leading to the interim 2021 Part L uplift.
- Home Energy Model: Replacement for SAP — Consultation — The dedicated HEM consultation covering the calculation methodology, software delivery model (ECaaS), and transition timeline.
EPC Reform Consultations
- Reforming Energy Performance Certificates — The consultation proposing the new four-metric EPC format using HEM-based assessments. See our EPCs & HEM guide for analysis.
- Improving the Energy Performance of Privately Rented Homes — MEES consultation proposing stricter minimum standards for private rented sector, with implications for landlords under the new EPC system.
Tools & Calculators
Software tools and calculators for energy modelling and FHS compliance. During the transitional period, SAP 10.3 software is used alongside early HEM implementations.
Current SAP Software Providers
These providers offer approved SAP 10 software and are expected to develop HEM-compatible tools. For SAP assessors, your existing provider is likely your best first contact for HEM training and migration.
- Elmhurst Energy — Design SAP and EPC lodgement software, plus assessor training and accreditation.
- Stroma — SAP calculation software, certification, and CPD training programmes.
- NHER (National Home Energy Rating) — Plan Assessor SAP software and energy consultancy services.
Professional Bodies
Industry organisations providing standards, guidance, and professional development relevant to HEM and the Future Homes Standard.
- CABE (Chartered Association of Building Engineers) — Professional body for building engineers, providing guidance on building performance, compliance, and energy assessment.
- CIBSE (Chartered Institution of Building Services Engineers) — Technical guidance including TM59 (overheating), TM52, and building performance standards. Essential for architects and engineers.
- RIBA (Royal Institute of British Architects) — Practice guidance, plan of work, and sustainability resources for architects working on FHS projects.
- NHBC (National House Building Council) — Standards, warranty, and technical guidance for new housebuilding. Publishes FHS readiness guides and hosts CPD events.
- Good Homes Alliance — Campaigns for better-quality new housing and publishes guidance on overheating, airtightness, and building performance.
- Passivhaus Trust — Guidance on low-energy design principles that align well with FHS fabric-first requirements.
Training & CPD
HEM training is being developed alongside the software. Existing SAP accreditation bodies are the primary route for energy assessors transitioning to HEM.
- Elmhurst Energy — Accreditation body for DEA and OCDEA qualifications. Developing HEM training programmes and early access to HEM-compatible software.
- Stroma Certification — Accreditation, certification, and CPD training programmes for energy assessors.
- Quidos — Accreditation scheme for energy assessors, providing training and quality assurance.
- NHBC Foundation — Publishes research and hosts CPD events on FHS construction practices, useful for builders and site managers.
- CIBSE Training — CPD modules covering building performance, overheating assessment, and low-carbon design relevant to HEM.
Further Reading
Our recommendations for quality third-party articles, reports, and guides that complement this site. We link to these because they genuinely help — not because of any affiliation.
- UK Housing: Fit for the Future? (Climate Change Committee, 2019) — The landmark report that recommended replacing SAP and set the trajectory for the Future Homes Standard.
- What is Passivhaus? (Passivhaus Trust) — Helpful primer on the fabric-first design principles that underpin much of the FHS approach to energy efficiency.
- NHBC Foundation Research — Practical research reports on new-build quality, including studies on airtightness, overheating, and the performance gap between design intent and as-built reality.
- Overheating in New Homes (Good Homes Alliance) — Detailed guidance on overheating risk that complements our overheating guide.
Our Other Work
This guide is published by Guy Smith of Every Property Certificate Ltd (easyepc.org). For EPC services across England and Wales — including domestic EPCs, new-build SAP calculations, and commercial SBEM assessments — visit easyepc.org. You can learn more about our qualifications and experience on our About page.
Keeping Up to Date
The transition from SAP to HEM is a moving target. Here are the best ways to stay informed:
- Our news section — Regular roundups of HEM and FHS developments
- Timeline & status — Live tracker of key dates and milestones
- GOV.UK email alerts — Sign up for notifications on the HEM technical documentation page
- Industry events — NHBC, CIBSE, and Futurebuild regularly host FHS-focused sessions
Frequently Asked Questions
Where can I find the official HEM technical documentation?
The Home Energy Model technical documentation is published on GOV.UK and through the BRE consortium. The core documents include the HEM technical specification, the Future Homes Standard consultation responses, and Approved Documents L, F, O, and S.Are there free tools for HEM energy modelling?
HEM is being developed as open-source software, meaning the core calculation engine will be freely available. However, commercial software providers will build user-friendly interfaces around it. During the transitional period, SAP 10.3 tools remain available from existing providers like Elmhurst, Stroma, and NHER.How do I respond to government consultations on HEM?
Government consultations on the Future Homes Standard and HEM are published on GOV.UK. When a consultation is open, you can respond through the GOV.UK portal. Industry bodies such as CIBSE, RIBA, and the Federation of Master Builders often submit collective responses and welcome member input.What training is available for the Home Energy Model?
Training for HEM is being developed alongside the software. Existing SAP accreditation bodies — including Elmhurst Energy, Stroma, and NHER — are developing HEM training programmes. CIBSE and NHBC also offer CPD events covering the Future Homes Standard and its energy modelling requirements.Where can I find the latest HEM news and updates?
Our news section covers the latest developments in HEM and the Future Homes Standard. For official announcements, monitor the GOV.UK Future Homes Standard page and the Building Regulations consultation portal. Industry bodies including NHBC, CIBSE, and the Good Homes Alliance also publish regular updates.Related Pages
What is HEM?
An accessible introduction to the Home Energy Model and what it means for the UK.
Future Homes Standard
Complete guide to the FHS including Part L, ventilation, overheating, and compliance.
EPCs & HEM
How Energy Performance Certificates are changing under the Home Energy Model.
News & Updates
Latest developments in HEM, FHS, and EPC reform.